The Sun’s visible surface, or photosphere, is 10,000 degrees Fahrenheit. As you move outward from it, you pass through a tenuous layer of hot, ionized gas or plasma called the corona. The corona is familiar to anyone who has seen a total solar eclipse, since it glimmers ghostly white around the hidden Sun. This [continue reading]
X-ray observations have revealed something curious about the young star that illuminates McNeil’s Nebula, a glowing jewel of cosmic dust in the Orion constellation: The object is a protostar rotating once a day, or 30 times faster than the sun. The stellar baby also has distinct birthmarks—two X-ray-emitting spots, where gas flows from a [continue reading]
Venus is a rarity among planets – a world that does not internally generate a magnetic field. Despite the absence of a large protective magnetosphere, the near-Venus environment does exhibit a number of similarities with planets such as Earth. The latest, surprising, example is the evidence for magnetic reconnection in Venus’ induced magnetotail. Solar wind [continue reading]